USAF won’t resume full F-35 buys until Lockheed wrings problems from upgrade: service chief

ROYAL AIR FORCE FAIRFORD, England—Lockheed Martin needs to make progress on a host of delayed upgrades to the F-35 fighter jet before the Pentagon will return to buying the jet in planned levels, the Air Force’s chief said. Frustration over delays with the Block 4 upgrade—coupled with a broader Pentagon budget reprioritization—led the service to request just two dozen new jets in its 2026 budget proposal—half of last year’s plan and down from the 44 bough